MOSCOW – President Vladimir V. Putin of Russia signed a decree late Monday night formally recognizing Ikraine’s Crimea region as a “sovereign and independent state,” defying the United States and Europe just hours after they imposed their first financial sanctions since the crisis began and laying the groundwork for possible annexation.

Putin’s decree came after the breakaway republic formally declared its independence and asked Russia to annex it in keeping with the results of a referendum conducted Sunday under the watch of Russian troops. The Kremlin announced that Putin would address both houses of the Russian parliament today, when many expect him to endorse annexation.

The moves showed that Moscow had no intention of backing down in the face of Western sanctions over a dispute that has created a profound rift in East-West relations and threatens the security of borders created after the Soviet Union’s breakup in the early 1990s.

Even as the Kremlin announced Putin’s decree, all the factions in Russia’s lower house of parliament submitted draft legislation that welcomed Crimea’s referendum, reversing a decision made 60 years ago by Soviet leader Nikita S. Khrushchev to put Crimea under the authority of what was then the Ukrainian Soviet Socialist Republic.

The resolution pledged to “to contribute to the social and economic development of Crimea and the prosperity of its population, to maintain peace, calm and conciliation on this territory during the transition period.”

Earlier Monday, the United States froze the assets and banned travel for 11 Russian and Ukrainian political figures, including top aides and allies of Putin as well as former President Viktor Yanukovych of Ukraine, whose ouster following pro-Western street protests last month prompted the Russian military incursion into Crimea. The European Union followed suit with sanctions against 21 Russians and Ukrainians, although none as prominent as those on the U.S. list.

“We’re making it clear there are consequences for these actions,” Obama said in a televised statement in the White House briefing room Monday. “The international community will continue to stand together to oppose any violations of Ukrainian sovereignty and territorial integrity.”

In a conference call to brief reporters Monday, administration officials said Obama has created a new set of sanctions that, while targeting a limited number of individuals at first, has a broader scope than any aimed at Moscow in decades.

Among those penalized Monday were Vladislav Surkov, for years one of Putin’s most influential advisers, known as the Kremlin’s “gray cardinal”; Sergei Glazyev, an economist who has been advising Putin on Ukraine; Valentina Matviyenko, chairwoman of the Federation Council, the upper house of parliament; and Dmitry Rogozin, a deputy prime minister. No sanctions were placed on Putin.

Obama sent Vice President Biden to meet with leaders of Poland, Estonia, Lithuania and Latvia, NATO allies that feel especially nervous about Russia’s actions. The president leaves for Europe next week on a previously scheduled trip that may focus on the Ukraine crisis.